First Pass Yield Calculator
Calculate first pass yield, first-pass defects/rework and final recovered yield from production input and quality results.
Calculate First Pass Yield (FPY)
Measure the share of input units that meet quality requirements the first time without rework, repair, retest or rerun.
First Pass Yield formula
ASQ describes first-pass yield as the percentage of units that complete a process meeting quality requirements without scrap, rerun, retest, repair or rework. In this calculator, FPY = first-pass good units ÷ units entering × 100. ASQ First Pass Yield resource.
Why FPY is different from final yield
A process can ship nearly all input units after rework and still have poor FPY. That distinction is valuable because rework consumes labor, capacity, material, inspection and lead time that final-yield reporting can hide.
Define the process boundary
For useful comparisons, keep the entry point, quality criteria and definition of “first pass” stable. If a unit leaves the process for repair and returns, it should not be counted as first-pass good simply because it eventually passed.
Use FPY with defect information
FPY tells you how much flow succeeds without correction, but not why units fail. Pair it with defect categories, rework time/cost and process-step yields to prioritize improvement work. Multi-step Rolled Throughput Yield can reveal compound losses across an end-to-end process.
Trend FPY at the right level
Plant-wide FPY can improve simply because the product mix changed toward easier items. Segment by product family, process, shift or defect mode where appropriate, and preserve the same inspection standard. If measurement-system error is significant, apparent FPY changes may reflect inspection variation rather than process improvement. Pair the percentage with absolute volume so a small high-volume decline is not hidden by a high overall rate.